Forums > Specific Focus > Technical Mexico

johnv

Sep 29, 2003, 8:29 AM

Post #1 of 8 (779 views)

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1.2 meter dish antenna

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I have a 1.2 meter offset dish antenna, purchased in México, of unknown specifications and manufacture. Does anyone know how to determine the offset angle and focal distance(point) through measurements, calculations, or other means. I would also be able to email a picture of the antenna to anyone who might be able to identify its manufacture and/or specifications.

johanson / Moderator

Sep 29, 2003, 10:54 AM

Post #2 of 8 (763 views)

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Re: [johnv] 1.2 meter dish antenna

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John.

I'm guessing by your question, that you have acquired this dish to use in Mexico with a satellite system from up North, probably Star Choice.

I've installed perhaps 10 small dishes. over the years. I have never known what their offset angle was. I have looked, taken a guess and then pointed in what I thought was the correct direction and elevation, and then according to how well I guessed, it took me from 5 minutes to an hour to get a signal.

If I guessed at what you are trying to do correctly, you can get pointing information from www.lyngsat.com Go to the satellite you want to point at. It will take a while to figure out this site, but its great. If you happen to be setting up a dish for Star Choice the actual link you would want to go to is

http://www.lyngsat.com/tracker/anikf1.shtml

Once there click on the map where you think you're at, check to see that your Lat and Longitude looks right and there are your Az. and El. settings. Good luck

johnv

Sep 30, 2003, 7:26 AM

Post #3 of 8 (741 views)

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Re: [johanson] 1.2 meter dish antenna

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Yes, I did purchase this antenna to use with StarChoice. The reason I asked about offset angle and focal distance is because of the problems I am having aligning the dish. I have spent far more than an hour trying to receive a substantial signal. Mike Kohl at Global Communications, who sold me the receiver and LNBF, has not been of much assistance with my problem. He says that he is unable to give advice about aligning an antenna of unknown specifications and that I wouldn't be having this problem if I had bought his antenna. The reason I asked about focal distance is because my antenna has a rectangular receptacle on the LNBF arm and I have attached a 40 mm adapter in order to hold the Pansat PF-7600 LNBF. I attached the 40mm adapter by inserting a wooden extension into the rectangular receptacle and then clamping the adapter to the wooden extension. This locates the LNBF up to 3.5 inches farther from the dish than it is supposed to be. The LNBF appears to point at the center of the dish give or take 1.5 inches. I am using an elevation of 64.4º and an azimuth of 196.4º which is correct for the city of Guanajuato. I have tried elevations of 30, 34, 38, 42, 46, 50, 54, 58, and 62 degrees in order to compensate for unknown offset angle. I have tried azimuths between 180º and 210º in one degree increments. No matter what I do the meter reading never varies from 20. It even reads 20 if I turn the antenna around and point it due North. I have a feeling that my problem may be in the fact that this antenna was made to use a DirectTV LNBF and that I have attached a "round type" LNBF by unconventional means. I find it very strange that the meter reading NEVER varies from 20 no matter what I do to align the dish. Any advice in this matter would be greatly appreciated. Thankyou very much.

Rolly

Sep 30, 2003, 9:05 AM

Post #4 of 8 (729 views)

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Re: [johnv] 1.2 meter dish antenna

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Two questions: Are you sure the meter is OK? And have you tried aligning with the reciever and a TV set -- that is how my dish was aligned, and it worked well.

Rolly Pirate

E-visit me http://Rollybrook.com
On Facebook as Rolly Brook

johanson / Moderator

Sep 30, 2003, 9:33 AM

Post #5 of 8 (726 views)

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Re: [johnv] 1.2 meter dish antenna

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The fact that you always have the same reading of 20 does not sound right to me. If I were in Ajijic, I arrive Thurs, I would phone a friend who has installed hundreds of these systems with local dishes. Yes the focal point makes a difference, but you should still get a signal. When going from point to point don't rush, I know when I am in a hurry, I will not stay long enough at a point to allow the system to acquire the signal. How long do you have to wait? That is a question I would have for my friend, but its more than a few seconds.

. In Ajijic, I would go to a neighbor's house (we have maybe 800 starchoice systems down here) and first exchange my receiver with his, and then if we were good friends do the same with the LNBF

If you haven't figured out what the problem is in the next few days, or if another reader does not have a better idea, re-post and I will phone up an installer in Ajijic and ask what he thinks.

Good luck.

PS I had a star choice receiver with me the day the new satellite when hot and had a signal within a few hours of the time the satellite went hot. When was that? About Feb 21st perhaps 2002?

johnv

Oct 2, 2003, 10:10 PM

Post #6 of 8 (694 views)

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Re: [johanson] 1.2 meter dish antenna

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It would be greatly appreciated if you could phone the installer when you return to Jalisco and post any information. Also you might ask him if he knows of an installer, who is familiar with StarChoice, in the Guanajuato/Leon area. Thankyou very much. John V

johanson / Moderator

Oct 3, 2003, 8:34 AM

Post #7 of 8 (681 views)

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Re: [johnv] 1.2 meter dish antenna

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Hi John. I just got back to Ajijic midnight, Wed night, Thurs morning. I had to phone both my 4DTV and Star Choice providers to get re-hit, to get my signals working. I will definitely check to see if any of my contacts know of an installer in your area, or of even a star choice user. I'm sure they are there. I am just not sure where.

(This post was edited by johanson on Oct 3, 2003, 8:36 AM)

johanson / Moderator

Oct 3, 2003, 2:38 PM

Post #8 of 8 (663 views)

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Re: [johnv] 1.2 meter dish antenna

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I spoke to several Star Choice experts, none of whom knew of any installers in your area. They talked about several very simple errors some self installers had done, like pointing the LNBF at the satellite rather than the dish, something I am sure you didn't do. One of them offered to talk to you on the phone and tell you his experiences with self installs and the problems he usually discovered.

Send me a private email if you are interested and I will give you his local phone #.

Pete